Gas sealed incandescent lamp or the like



April 17, 1934. v E. MUKASA (ms SEALED INCANDESCENT LAMP 0?: 2mm LIKE Filed Nov; 1%, 1931 Patented Apr. 17, 1934 PATENT OFFICE GAS SEALED INCANDESCEN'I Lm I)! THE LIKE smuumsmmsnmtmnan,

Tokyo Fu, Japan, aasignor to Toden Kabuahiki Kwaiaha, Shinagawa Iaehi,

Gun. Tokyo Fu, Japan Ill-ta Application November 1:, 1031, Serial No. 575,921 In Japan January 12, 1981 scum.

My invention relates in general to gas sealed incandescent lamps, and more particularly per-, tains to that type having inherent characteristic for protecting its base and sealed part against being overheated.

With gas sealed incandescent lamps, it has hitherto been proposed to protect the base against being overheated, for exampleby a vacuum wall around the neck of the bulb. This prevents the base but not the sealed part, from being overheated; moreover its manufacture is rendered diflicult and troublesome.

It has also been proposed to provide a disk made of mica or like material closely fitted inside the neck of the bulb beneath the sealed part, so as to restrict the convection of gas in the lamp bulb below said disk. But inasmuch as the disk is heated by the gas circulating below it at high temperature, the gas above the disk becomes also heated and is caused to circulate above the disk, whereby the base and the sealed part are heated after all. This method, therefore, is not successful and experiments show that it is not practically useful.

According to the present invention said overheating of the base and the sealed part are entirely avoided and the manufacture of the incandescent lamp is rendered easy and economical.

Stated more specifically, it is. proposed to fill glass wool or the like material in the space of the neck around the sealed part in the gas filled incandescent lamp, so that the base and ,the sealed part may be kept perfectly free from being overheated. By diminution of the surface area of the bulb at high temperature, from whence heat is dissipated into atmosphere, watt consumption of the incandescent lamp or other similar means is considerably economized.

In the accompanying drawing Fig. 1 shows a longitudinal sectional view of the incandescent lamp embodying the present invention, Fig. 2 shows a longitudinal sectional view of the modifled form.

Referring to Fig. 1 the bulb (1) is provided 45 inside with a filament (3) or electrodes of arc or any other electrically radiating means. Projecting inside the bulb 1) and passing hermetically through the sealed part (6) are the lead wires (4). The base (2) is attached at the top 50 (8) of the neck (7) to which the upper end of the stem tube (9) is connected. Glass wool or the like non-conducting material (5) is filled in the space of the neck (7) around the sealed part (6) and the stem tube (9). A disk (10) made of glass or any other non-conducting material is provided for. the glam wool (5) in case of necessity.

Woolglassisafineandflexiblefibreofglass, and provides a highly non-conductive material. It contains no volatile matter, and does not dis turb the glass for being fused together in the course of manufacture of the bulb, and even when apartofglaswoolisfusedtogetherwiththe glass noharmfulefi'ectisbroughtonthe nature of incandescent lamp. Glass wool is therefore, bestadaptedforthepurposeasstatedabove.

The improved I lamp of the present invention being provided with glass wool or like non-conductive stufi'lng material in the neck (7) hot gas heated by the filament or any other electrical heat producing means (3) and furiously circulating in the bulb (1) by convection is interrupted, and the base (8) and the sealed part (6) are perfectly protected against being overheated by means of said non-conductive stuiflng material.

In the modified form shown in Fig. 2, glass wool (5) is received in a thin metal case or cage (10) in place of a disk (10), closely fitted inside the neck ('I). The case (10') may be perforated or made of a fine wire netting. Lead wires (4) are insulated from said case by glass tubes (11). According to this modified form glass wool (5) may be filled into the casing (11') in order to protect the sealed part (6), and the metal case will thus prevent fragments of glass wool from falli into the bulb (1).

Lossesofenergyingassealedlampsarechiefiy divided into two kinds. One of which is the heat loss directly radiating from the white heated filament, and the other the heat radiating into the atmosphere by the air coming in contact withthebulbwallheatedbytbesealedgasin the bulb. With a bulb of ordinary shape, the latter 10s is nearly p onate to the surface areaofthe bulb. Acoordingtothepresent invention the heated surface of the bulb being diminishedbytheareaoftheneck ('1),thedissipating heat is saved, and the electric power for keeping the filament or other heat producing means at constant is considerably economized.

The incandwoent lamp of the present inventionisproducedbymerelyfillingwoolglassin thespaoeofthenecksothatthemanufacture of the lamp is easy without need of a special machine.

Whether the disk (10) or the metal case or cage (10') is provided for supporting the glass wooLthelowersidethei-eofmaybeamirror or be painted white in order to reflect the rays of the filament. Having now particularly described and ascer- V tained the nature of my said invention, and in what manner the same is to be performed I declare that what I claim is:-

1. The combination with an incandescent lamp having a gas-filled bulb with a sealed neck portion, leading in wires projecting into the bulb from said sealed neck and electric heat producing means at the inner ends of said wires; 0! a non-conducting stufling material filled inthe space of said neck. surrounding the sealed portion.

u 2. In an incandescent lamp as described in claim 1, said stufllng material consisting of glass claim 1 ,saidstufling materialconsistingotglass' wooLandmeanssupportingtheglasswoolin theneckspace,saidmeanscomprisingametal cage having a reflecting bottom suriace.

v EIZOKUKASA. 

